An hierarchical routing protocol for opportunistic emergency networks

In critical and emergency scenarios such as disasters, first responders must setup mobile networks in order to address the lack of a functioning network infrastructure. Communication in such scenarios may be susceptible to long interruptions, and as a consequence we must employ DTN-based (Delay/Disruption Tolerant Networks) communication protocols. Existing routing approaches suitable for emergency scenarios tend to consume a large amount of resources, due to the stochastic behavior of node movement. This paper has two contributions. First, we propose a resource-efficient DTN routing protocol, called HIerarquical Group ROuting Protocol (HIGROP). HIGROP aims to reduce the forwarding overhead by the use of node clusters, while maximizing the message delivery rate. The second contribution is the definition of a new mobility model, called MME, which emulates the movement patterns of first responders in search and rescue scenarios. We compared HIGROP against Epidemic and Prophet protocols and noticed that it is scalable and has a lower communication overhead.